Most of the lock traffic is now on summer afternoons when energy usage is lower (in my childhood you would see tugs pulling a line of coal barges up to Kingston power station) and water passing over the weir is wasted energy that this would use.
But for just 100kW I think this one is best left for another day ...
Utter bollocks.
In the UK we *effectively* have.
Not much North sea gas left, coal so uneconomic and dangerous to mine...
The UK is a en energy poor country.
Yup. you can get more from a bio-diesel engine.
Apparently the KE in the water is irrelevant for a traditional water wheel. You want a nice slow fill for maximum efficiency, so undershot wheels are fine.
cheers, clive
I'm not sure what your point is because it seems to be saying much the same as I did except a qualification you seem to infer is it's not worth trying.
We're agreed that a high head (potential) and low flow (current) is easier to exploit than a low head high current. I wonder if there is any parallel here with electronics. In the beginning a valve radio needed a low voltage heater supply and a high dc voltage for the signal, over time the science has evolved to make use of low dc sources to run radios, OK it's not a direct parallel and the scaling is opposite but advances coupled with rising energy costs may make it worthwhile.
I also indicated the catchment area needed for a hydro scheme was very large but the thing I was musing about was that whilst we have already picked the cherries with impoundment schemes there may be harder fruit available if we can accept some compromises over scheduling.
BTW I have consistently said I think increased use of nuclear power is inevitable.
AJH
Again you have misrepresented my point and I will leave it to others to judge. I made it clear that both height and flow were proportional to power. You have not made any point that was not already discussed neither have you understood the point that the dam impoundment is to control the flow, it does not inherently increase the energy in the water.
The total power available from this resource would be the same if a pipe ran around the contour of the hill at the same height of a dam, but in its absence, and fed the penstock, it would just have a lot less utility.
I was referring to a specific case, the dam at blackwater above Kinlochleven, here a fairly shallow dam impounds water about 7 miles from the hydro electric plant, there is a long shallow "leat" that runs along the contour to the penstock which is 1200ft above the generating station, so the height of the dam and the water behind it is insignificant compared with the fall through the penstock, I used it as an example of something I was familiar with.
Had you queried my meaning in a civilised manner I was quite happy to expand on it or rephrase it if my meaning was unclear, I enjoy the banter here and I've learned lots from usenet but see no need for unnecessary offensiveness.
Actually I realise I inferred something from Natural Philosopher's post that was wrong. He was quite right in saying "That is why you build dams where there is a lot of water than can fall a long way."
I was wrong to infer that he was considering a dam increased the power rather than the economic aspect. I commented on it because I am interested in how variable and erratic renewable energy can be fitted in to our energy needs (which seem to be remarkably regular and consistent from the graphs at the nationalgrid.com site).
AJH
I can see that for the feed into the bucket and am not familiar with waterwheels in general but the angle of the bucket must dictate how the water is discharged, what part of the potential is not used and the velocity of the water as it gets away. I know the Pelton wheel maximises its conversion by having its cups running at half the water velocity so the water discharges at zero velocity. Anyway for now I'd be quite happy just to see a comparison on the conversion efficiency of each type.
AJH
Still bollocks.
You keep quiet on the subject of oil, and it's a travesty to claim that coal mining is uneconomic or particularly dangerous. It's certainly not exhausted, last estimates of UK reserves of coal that I saw still indicated sufficient for a century. At present it's uneconomic to mine because of cheap imports of opencast coal. But that doesn't mean that the reserves have "run out."
Oh right it must be so because you've said it.
I'm sorry that's simply wrong. Undershot wheels are inherently inefficient, pitch-back wheels are most efficient, overshot next best, undershot poorest of all. Also undershot wheel rely entirely on the KE of the water, whereas overshot relies on the potential energy (i.e. head) of water and pitchback uses both (the PE from the head and the KE from the flow of water).
The only reason for using undershot is when there is no possibility of creating sufficient head of water for an overshot or pitch-back wheel.
Without the dam you will not be able to exploit the head of water, other than by using another device (such as a pipeline) to maintain the head of water.
You can f*ck off with the "don't udnerstand" rubbish while you keep talking drivel.
Ah - I'm not thinking of undershot at all - I'm thinking of high breastshot - which isn't too inefficient, and doesn't use the KE of the water.
clive
Which is the point I made.
As you wish but you proved my point as you wriggled you argument around.
AJH
And discredited himself by using offensive language.
Mary
Utter bollocks, and you just did (again).
To state that a dam does not affect the power available is drivel, pure and simple. Without constructing a dam, there is no available head of water from which to generate power.
Sorry, should have added a smiley as it was meant as tongue in cheek. From what I recall, having been cavorting in a caravan in Rhyl with Carol Vorderman at the time :) It was known as Dinorwic throughout its construction, and all the original drawings are clear on this point. Only after a few years operation did it get its current "proper" name.
Yes, expensive petrol tends to stop that.
I've got a relative who moved into the area from England in the past couple of years. They are only there because there were no suitably qualified locals available that could do the job. House prices at first glance seem no worse then elsewhere. Pity most of it is pebbledashed :) Are you still getting welsh nationalist graffiti on the stone walls adjoining the A55?
I agree, It's time that jetski's were banned, the Howard's Way brigade though can bring valuable income to the area.....what a shithole Pwllheli would be without the marina. But just imagine what it would be like with the traffic if the toerags hadn't burnt down the original Britannia Bridge and .......seems to be a common theme here, the Welsh and fire :)
What did you expect? It's the dragons, see...
And educated guess would be the pelton around 65% and the over or undershot wheel about 2%.
I have yet to see an oil well in this country.
There isn't a lot left offshore either.
You are joking...its either uneconomic or dangerous. Its certainly one
*or* the other.
Economically they have, There is plenty of it but the cost of *safe* extraction renders it infinitely more expensive than other fuel forms.
No, because it IS. All the easily exploitable resources have been easily exploited already.
What a revealing comment! If you cycle or walk to Dorset (such a 'green' method of travel) then your experiences will be enhanced and your list of 'things I have seen' will be added to.
The North Sea has so dominated public perception of Britain's oil production that one could be forgiven in thinking that it was the only domestic source of oil. This is far from the truth. There are a number of on-shore oil fields in the UK - the most prolific of which is Wytch Farm in Dorset. Wytch Farm has produced over 400Mbbl (million) ...
BTW; "I have yet to see; Tony Blair; John Major; The Angel of the North; London Eye; Birmingham's Selfridges; ... nor an oil well; in this country" :( { However, they probably exist ...}
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.